A bi-level lighting system (which may also be referred to as an A/B lighting system) may control lighting in an area, such as, e.g., a commercial, residential, or industrial space, and may typically provide two levels of partial lighting between an “all lights off” state and an “all lights on” state. For example, some known bi-level lighting systems may have a first partial lighting level that turns on 25% of the lighting in an area (e.g., one light bulb or fluorescent tube out of every four) and a second partial lighting level that turns on 75% of the lighting in that area (e.g., three light bulbs or fluorescent tubes out of every four). Such bi-level lighting systems may typically include a pair of switches located in, e.g., a wall-mounted dual-gang switch box. The pair of switches may be connected in the switch box to an AC utility power source. Associated wiring between the switch box and the lighting may include an “A load” conductor for connecting a first switch with every fourth light bulb or fluorescent tube, and a “B load” conductor for connecting a second switch with the remaining three light bulbs or fluorescent tubes of every four. To turn on 25% of the lighting, the first switch may be activated, which connects power to 25% of the lighting, while the second switch is deactivated, which disconnects power from the remaining 75% of the lighting. To turn on 75% of the lighting, the second switch may be activated, which connects power to 75% of the lighting, while the first switch is deactivated, which disconnects power from the remaining 25% of the lighting. To turn on all the lighting, both switches may be activated, which connects power to all of the lighting. And to turn off all the lighting, both switches may be deactivated, which disconnects power from all of the lighting. Energy savings with bi-level lighting systems, however, are limited because they provide only two levels of partial lighting.
A dimmable lighting system may allow dimmable lighting to be dimmed to any light level between 100% (all lights fully powered) and, e.g., 15%, 10%, or 0% (all lights off). Such dimmable lighting systems, therefore, provide a greater range of dimming and, thus, a greater opportunity for energy savings while still providing a desired or acceptable level of lighting during, e.g., periods of available daylight and/or non-occupancy. However, replacing an existing bi-level lighting system with a dimmable lighting system may require expensive and time consuming removal and/or replacement of existing wiring through largely inaccessible spaces, such as, e.g., inside walls and ceilings, in order to connect a dimming light controller, which may replace the bi-level switches in a switch box, to one or more dimmable lighting devices.
Accordingly, a need exists to provide systems, apparatus, and methods for replacing existing bi-level lighting controls and light fixtures with dimmable lighting controls and dimmable lighting devices without having to modify and/or replace the existing wiring of the bi-level lighting system.